1. Field of the Invention
The present invention generally relates to a backlight driving signal generator and, more particularly, to a backlight driving signal generator used in a liquid crystal display (LCD) controller.
2. Description of the Prior Art
With the rapid development in the flat panel display (FPD) industry, the LCD has become the most popular display media. However, a backlight unit is required to provide a light source in order to display visible images on the screen because the liquid crystal molecules are not luminescent.
Currently, most backlight units comprise cold cathode fluorescent lamps (CCFLs) or light emitting diodes (LEDs) as a backlight source. Cold cathode fluorescent lamps are driven by alternate-current (AC) power so as to prevent non-uniformity of luminance due to clustered gaseous ions caused by direct-current (DC) power. On the other hand, light emitting diodes are driven by DC power without inverting the input power into AC power.
The backlight units are driven in different ways according to the elements used in the backlight units. Therefore, it is crucial to provide an LCD controller capable of controlling the luminance of both cold cathode fluorescent lamps and light emitting diodes.
Generally, the controller for cold cathode fluorescent lamps is not compatible for light emitting diodes, and vice versa. It will bring forth more flexibility and convenience to use an LCD controller capable of controlling the luminance of a backlight unit when the backlight unit is implemented by using either cold cathode fluorescent lamps or light emitting diodes.